5-arylazorhodanines



S-ARYLAZORHODANINES Isaac Benghiat, Bronx, and John C. Howard, Norwich,

N.Y., assignors to Stautfer Chemical Company, a corporation of Delaware No Drawing. Filed Feb. 28, 1958, Ser. No. 718,446

7 Claims. (Cl. 260-158) This invention relates to S-arylazo-rhodanines and 3 substituted S-aryiazo-rhodanines and their preparation.

It is an object of this invention to provide a method for the production of new compositions which are formed by the reaction of rhodanine or 3-substituted rhodanines and aryldiazonium salts.

It is a further object of this invention to provide for the production of bactericidal and bacteriostatic materials of unusual effectiveness.

Other objects and advantages of this invention if not specifically set forth become apparent during the course of the discussion which follows.

Generally, it has been found that S-arylazo-rhodanines and B-substituted S-aiylazo-rhodanines may be produced by the reaction between rhodanine or 3-substituted rhodanines' and aryldiazonium salts in buttered solutions.

These new compositions of matter display unusual bacteriological activity.

More specifically, it has been found that new compositions of matter having a general formula, which may be considered as where R is hydrogen or a monovalent alkyl or aralkyl radical and Ar is a monovalent aromatic radical, may be produced by the reaction between rhodanine or a 3- substituted rhodanine and an aryldiazonium salt.

The reaction may be represented (using the second of the above formulae) as follows:

RN-CO RN--CO I l +ArNn+Cl-- CE so (EEG-Nam S \S In general, the 5-arylazo-rhodanines may be prepared by first forming an acid solution or suspension of aniline or a substituted aniline material. To this is added an approximately equivalent quantity of sodium nitrite to form a diazonium salt. To this is slowly added an equivalent amount of an acidic solution of the rhodanine corresponding to the product desired. During the addition, the mixture is desirably maintained at a temperature within the range about ()--5 C. In this fashion a solution is formed containing both the rhodanine and diazonium salt. This is then added to a cold aqueous solution of sodium acetate and the mixture allowed to stand for a period of time following which the separated product is filtered, washed and dried. It may be crystallized from a suitable solvent. Yields are on the order of at least about 90 percent. A wide number of products have been prepared in this fashion, as set forth in examples which follow and in the table.

Each of the compounds prepared through the process of this invention has been assigned a code number and reference hereafter to the compounds is the appropriate code number.

' The examples which follow are for illustrative purposes only and'are not to be construed as imposing limitations by means of 5 on the scope of the invention other than as set forth in the appended claims.

EXAMPLE I N-1162, 5-(phenylazo)-rhodanine 6 N HOl is diazotized by the addition of 0.1 1 gram-mole of sodium nitrite at 05 C. To the resulting solution of the diazonium salt a solution of 0.1 gram-mole of rho-' danine in 400 ml. of glacial acetic acid at C. is added slowly with cooling so that the mixture is maintained at 0-5 C. Theresulting solution which contains both the rhodanine and the diazonium salt is then addedwith stirring to a cold solution of 300 grams of sodiumacetate in 800 ml. of water. The product separates im-E mediately. When the addition is complete, the resulting. A thick slurry is stirred 45 minutes longer at 5 C. The mixture is allowed to warm to room temperature. It is then allowed to stand overnight. The product is-then filtered, ,washed several times with water and air dried.- It is then crystallized from a mixture of acetic acid and.

N-1 185, 3-methy l-5-( p-nitrophenylazo) -rh0danine The procedure described in Example I was followed using a suspension of 0.1 gram-mole of p-nitroaniline in 6 N HCl in place of aniline and using 3-methylrhodanine in place of rhodanine. The product was obtained in 92 percent yield. A portion was recrystallized from acetic acid for analysis. M.P. 267-268 dec. Analysis: Calcd. for C I-I N O S S, 21.6. Found: S, 21.3. The followmg compounds were prepared m a similar manner:

TABLE I Cgymmaund R Ar um er N-llfil H p-nitrophenyl. N-1197 H p-chlorophenyl. N-1202 H p-methoxyphenyl. N-1208 F1 o-tolyl. N-1220 CH5=CHCHzp-nitrophenyl. 5 N-1223 (OH3)gCH- p-bromophenyl.

N-1230 O H -(|}HCH p-nitrophenyl.

N-1242 CHQOOHICHQ- x,x-xylyl. N-1243 OH30CHzOH2CHzx,x-xylyl. N-1244 (OHz)gNGHzCH:CHz p-nitrophenyl.

N-1285 H p-nitrophenyl.

HOOOOH p-nitrophenyl.

pnltrophenyl p-mtrophenyl 2,4 dinitrophenyl 2,4-dichlorophenyl. p-biphenylyl.

a-naphthyl. fl-naphthyl. p-ethoxyphenyl m-nitrophenyl. o-nitrophenyl. p-nitrophenyl.

N-1667 n-OnH p-nitrophenyl. N-l676 O o-chlorophenyl. N-1678 C- m-chlorophenyl. 1531 (1H1 p-chlorophenyl.

N-1688 n-CgH p-nitrophenyl.

Patented Sept. 13, 1960 A solution of 0.1 gram-mole of aniline in ml. of

In making thefollowing'tests, the varionscornpounds infthe concentrations indicated weremixed withnutrient agar in Petri dishes and inoculated with three species of bacteria. The bacteria usedwere Staphlococcus aureus,

Escherichia coli andwErwiniavzzmylovora. The. antiseptic action was indicated by the absence oigrowth'ldesignatedz by a zero growth being designated by ;a plus sign (5+). /At points (A) inrthe table, only 0011' showed growth; At all other points, all bacteria were controlled at the concentrations given. The concentrations are in parts per million based upon the quantity of agar present.

TABLE 11 w,

2500 1000 :500 1250 '100 50 p.p.m.' p.p.m. p.13 p pnn. p.p.m. p.p.m

0 V 0 7 VA A 0 0 0 0 As can be seen from'the above, thecompounds of the m where 'R is selected from the class consisting of H, alkyl groups of less than 13 carbon atoms, lower alkenyl, lower alkoxy-substituted lower alkyi, amino-substituted lower alkyl, lower cycloalkyl, benzyl, chloro-substituted benzyl and HOOCCH and where Ar is selected from the class consisting of phenyLJlowei' alkyl-substituted phenyl, nitrophenyl, dinitrophenyl, loweralkoxyphenyl, chlorophenyl, bromophenyl, biphenyl and naphthyl.

instant invention are effective bactericides even when applied in relatively low concentrations v Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereot, and therefore only such limitations should be imposed as are indicated in the'appended claims. V

We claim: V

1. Arylazo-rhodanines of the general formula: nN- -oo 5 s V OH-N=NAr i/ 1 5-p-nitrophenylazo-rhodanine.

. 5-phenylazo-rhodanine.

. 3-methyl-S-p-nitrophenylazo-rhodanine. 5-p-chlorophenylazo-rhodanine.

. 5-p-methoxyphenylazo-rhodanine.

. 5-o-tolylazo-rhodanine. v

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Elderfield: Hetercvcyclic Compounds, vol, 5, pp. 715- 716 (1957). 

1. ARYLAZO-RHODANINES OF THE GENERAL FORMULA: 